'NonStreaming Mips' and 'Unstreamable Render Assets'

Got this issue where all of a sudden this big memory hog appears and can’t figure out what it’s about. Upping my texture pool obviously clears up the issue, but it’s strange. When looking through the logs, all my nonstreaming textures only come to about 100mb, so where is that extra 1000+mb coming from?

Found a similar topic, but no solution was ever posted.